APPENDIX. 337 



ing to the flagellata. It is of an elongated, spindle-shaped form, with a nucleus, 

 and has a flagellum at one end, which extends along a thin edge, called the 

 undulating membrane. It is actively motile. It occurs in the blood, between, 

 but not in, the blood-corpuscles. Its length is two to several times the diameter 

 of a red corpuscle. Members of this genus are the cause of surra (a fatal dis- 

 ease of horses and mules occurring in India and the Philippine Islands) and 

 of the tsetse-fly disease of South Africa; while others are found in rats, birds, 

 amphibia and fishes. In the horse the infection is transmitted by the bites of 

 flies. Novy and MacNeil have succeeded in cultivating the tiypanosoma of 

 rats and birds on rabbit-blood-agar.* 



Several cases were reported during igoa where trypanosomes were found 

 in the blood of individuals from tropical Africa, showing that this group of 

 parasites may occur in man.f The symptomatology of these infections re- 

 quires further study. Still more recently it has been claimed by Castellani 

 that a trypanosoma is the cause of "sleeping sickness," a disease of the natives 

 of Africa. He states that the parasites may be demonstrated in the cerebro- 

 spinal fluid obtained by lumbar puncture and, with greater difliculty, in the 

 blood, during hfe. Many cases also show at autopsy streptococcus infection, 

 which is believed to be a secondary invasion. J 



* Loc. cit. 



t British Medical Journal. May 30, 1903. 



X British Medical Journal and Lancet. June 20, 1903. 



29 



